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mbrlen(3)

NAME

     mbrlen -- get number of bytes in a character (restartable)

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <wchar.h>

     size_t
     mbrlen(const char * restrict s, size_t n, mbstate_t * restrict ps);

DESCRIPTION

     The mbrlen() function inspects at most n bytes pointed to by s to deter-
     mine the number of bytes needed to complete the next multibyte character.

     The mbstate_t argument, ps, is used to keep track of the shift state.  If
     it is NULL, mbrlen() uses an internal, static mbstate_t object, which is
     initialized to the initial conversion state at program startup.

     It is equivalent to:

	   mbrtowc(NULL, s, n, ps);

     Except that when ps is a NULL pointer, mbrlen() uses its own static,
     internal mbstate_t object to keep track of the shift state.

RETURN VALUES

     The mbrlen() functions returns:

     0	     The next n or fewer bytes represent the null wide character
	     (L'\0').

     >0      The next n or fewer bytes represent a valid character, mbrlen()
	     returns the number of bytes used to complete the multibyte char-
	     acter.

     (size_t)-2
	     The next n contribute to, but do not complete, a valid multibyte
	     character sequence, and all n bytes have been processed.

     (size_t)-1
	     An encoding error has occurred.  The next n or fewer bytes do not
	     contribute to a valid multibyte character.

EXAMPLES

     A function that calculates the number of characters in a multibyte char-
     acter string:

	   size_t
	   nchars(const char *s)
	   {
		   size_t charlen, chars;
		   mbstate_t mbs;

		   chars = 0;
		   memset(&mbs, 0, sizeof(mbs));

ERRORS

     The mbrlen() function will fail if:

     [EILSEQ]		An invalid multibyte sequence was detected.

     [EINVAL]		The conversion state is invalid.

SEE ALSO

     mblen(3), mbrtowc(3), multibyte(3)

STANDARDS

     The mbrlen() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

FreeBSD 5.4			 April 7, 2004			   FreeBSD 5.4

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